Takeshi Aiza  

, 相座 武士

Takeshi possesses an honest and straightforward personality, often being direct about his feelings towards Kousei Arima. Initially, he harbored hatred and resentment for him, but this was later revealed to be admiration as he looked up to Kousei as a hero. Takeshi's respect for Kousei is so profound that he rebukes him when he fails to meet expectations as a pianist. Renowned for his exceptional piano skills, Takeshi has been invited to participate in European competitions and has won numerous recent piano contests in Japan. Prior to the storyline, Takeshi and Emi Igawa were sitting together criticizing Kousei after losing to him in a competition. The crowd acknowledged their superiority, making Kousei even more invincible due to his victory over them. In the narrative, it is clear that Takeshi admired Kousei as a hero and devoted himself to surpassing him through rigorous practice.